1. Field of the Invention
The present invention relates generally to a semiconductor device, and more particularly, to a method for fabricating a cylinder type capacitor which is capable of ensuring a capacitance.
2. Brief Description of Related Technology
With increase in an integration degree of a semiconductor device and sharp decrease of a design rule, development of a method for fabricating a capacitor which is capable of ensuring a larger capacitance within a limited area is required. In a Dynamic Random Access Memory (DRAM) device in which a cell transistor and a cell capacitor form a unit memory cell, it is necessary to ensure a larger capacitance for the improved operation of the memory.
To ensure the larger capacitance within a limited area, a storage node in a cylinder type is formed to increase the effective surface area of the capacitor. By increasing a height of a cylinder type storage node and exposing not only an inner wall of the cylindrical storage node but also an outer wall to contact with a dielectric layer, it is possible to increase an effective area of the dielectric layer.
As the height of the cylindrical node is increased and a spacing between the cylindrical nodes is narrow, falling down or leaning of the cylindrical nodes occurs in a wet etch process or a dip out process exposing the outer wall of the cylindrical node. Therefore, increasing the height of the cylindrical node is limited in the ensuring a large capacitance. To ensure a higher capacitance of the cylinder type capacitor, a method of preventing leaning of the cylindrical node is required.